Process for removing ink or coloring-matter from paper.



orgdiix juefmi'mim mom PAFEBI.

f .1 tented Magr li, 1916.

pronounced i's the d upon all the pulp recovered prooess'es knourn and described, is thetpohr sidefahlefltime is required in freeing: the 11ik, ujs ual1yj10 hours or more and when bleaching "3 involved, as high as 36 hours fer;sagtumtingicooking, washjh ingend;yeweehmgg 251 f proved piobess obviates all these ges andfproduces pulp which is it jfwh1t asth'e original; and; whlch retains l li of ts; adhesive qualities, so that ape? repared fro m iti s as strong"end durallle as hetlpjg-epered with freshly niadepulp, By hyfproeess one hour or moreWashing is all l le time requiredto prepare the-pulp a condition fit to be remade into Whlte paper. @Idpreparing chemical pulp, wood that esbeer l reducedtochipssis conveyed to a digeeter whereit is zicted upon by either a ulfureu s or an alkaline solution for about ighthOuI-S, the liquor'is then drawn off and heretofore hes been disposed of as a waste rodjuctt These spent or wastedigester liquor haveibeenfl found to be very detri y nv ntlmwm w r :removmg the hjythe sewer, they have been found to "zrim'ental to fish, the efi'ects the liquor beingsuch as to cause proposed laws equii-mg the evaporating and burning of re of eyerysolvent nature, and I have dis ovel ed -that by subjecting waste print pz'tpr'gfeither in a pulped state or in the wholeyto the action of either of these epept ligestrdiquors, under any temperature, for thespece of one hour or more, then. Washing nghutttepthet may he in the paper will be he chai ged into a heater Net filled e hexfiof thesespentdlg'ester liquors heaetion of thebbeating engine, all floring matter will he ehtirely freed on h 91111 b-[tyand the pulp washed in fresh the same in a state to be yei'nuide nto white paper rated almv e ll :mi aware of the sevmilled, the removing inkhr' coloring 1's 1? the mechanical wood pulp, the s'ame fitto he remade mto hme Ifthey wastelpapev'be first pulped, l 100 V theasolvent may then he ll ther disadvantage of-thelsblvents or mental 0 landtand if they are disposed of thewsolutiorish These spent -digester liquors ,he pulp with fresh water, all ink 01* cele eritirlyl removed, and Without" discoloring methods of processes heretofore known 110" l matter from waste papers by the use of cially prepared solvents, but I'am not aware of any one using either of these spent digester liquors for that purpose, therefore I desire to claim that broadly.

What I claim is:

1. The process of removing ink, colo matter onpigments from waste ap is f" y the ,use of spent digester liquid equivalent of such waste digesterliquids.

'2. The process of recovering a1l pul from waste papers, made partly of mechanr H cal wood pul consists of thef following steps: (1)" pu ping the waste'pa ers; (2) subjecting the p ll draining andl'washing the material in fresh .water; (4) separatin the pulp fibers the impurities and co lecting the clean pulp,

the action of spent s, -'or-the to the aetion o spent di-I gester liquids un er any temperature; (3)

from

substantially as set forth.

' The process of recovering all pulp from waste print papers, made partly of mechanical wood pulp, consists of the following E. F. BOND. 

